U.S. Pat. No. 5,089,799 discloses an electric rocker switch capable of both conventional switch operation
and of thermal operation also. The thermally responsive movable contact element may be mechanically closed against the fixed contact, but is also movable by bimetallic thermal action to an open condition when an overcurrent condition exists. A trip flag is provided for movement between the open contacts whenever the switch rocker is moved to OFF, and will remain in this position if an overcurrent condition exists even if the rocker is held ON. Thus, trip free operation is achieved provided only that the flag first move between these contacts. A return spring is provided for the trip flag so that a positive action occurs as the flag moves between the contact. The same spring also holds the rocker in its ON position, and in addition this spring serves to hold the trip flag against the movable contact in the switch ON condition.
The general purpose of the present invention is to provide for an improved trip flag configuration such that the trip flag rests lightly on the movable contact of the bimetallic element, which trip flag is also designed to continue to bear only lightly on the movable contact when the rocker is moved from the ON position toward the OFF position.
One object of the present invention is to provide a trip flag mechanism whereby when the rocker is actuated from the ON position to the OFF position, the resulting forces thereby generated through the trip flag against the movable contact are either nonexistant or absolutely minimal. This is accomplished during rocker actuation to OFF by having a pivot point for the trip flag against the breaker base at a point higher than a line drawn between the point of pressure of the trip flag against the contacts and the point of pressure between the rocker and the trip flag.
Another object of the invention is to provide a trip flag mechanism that assures an initial rotating downward action of the trip flag prior to assuring the occurrence of a sliding downward action when the rocker is actuated from the OFF position to the ON position, thereby allowing for the contacts to come together to the ON position prior to the rocker cam being able to pass over the trip flag cam and then be latched in the ON position. This is accomplished during actuation to ON by having a different, lower pivot point for the trip flag against the breaker base than the pivot point that is engaged when the rocker is actuated from the ON position to the OFF position; this lower pivot point is configured to change its point of contact against the base as the trip flag rotates to assure the downward movement of the cam area once the trip flag has rotated adequately to allow the contacts to come together.